


The Devil You Know

by Inkaroni



Category: Voltron: Legendary Defender
Genre: Alternate Universe - Canon Divergence, Eventual Smut, Fluff and Smut, Galra Keith (Voltron), I Don't Even Know, Keith is still trying to learn how to lead, M/M, Not Season/Series 08 Compliant, Supportive Lance (Voltron)
Language: English
Status: In-Progress
Published: 2018-12-04
Updated: 2019-08-15
Packaged: 2019-09-06 21:50:54
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,822
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16841089
Author URL: https://archiveofourown.org/users/Inkaroni/pseuds/Inkaroni
Summary: Team Voltron is back on Earth. The Galra have been beaten back for now. The paladins are doing their part, helping restore the Earth, building human/alien relations and preparing for the next attack that inevitably will come.But until then Lance is just glad to be back on Earth. To be with his family and finally have solid terra firma underfoot. It is the most peaceful it has been for the paladins in what feels like forever and intends to enjoy it while he can.Now that things have calmed down though he's started noticing some odd things about their leader. Things he is positive he hadn't noticed about Keith before. Things that were distinctly... Galra.At first, Lance thinks he's imagining it but eventually it becomes impossible to ignore... and even more impossible to deal with.





	1. Chapter 1

**Author's Note:**

> Beware here there be typos!

Lance first notices it during training.

The Garrison had put together a top of the line training room on par with the one from the castle with help from Coran. There was even a shiny new gladiator to kick their asses. It was hilarious to watch the MFE Fighter team get swept and get a taste of the hell they'd gone through. Kinkade held his own pretty well though so Lance has to give him props.

The Garrison was rebuilding, as was the rest of the world and the paladin’s wounds and concussions had healed after their tangle with the mysterious murder robot and the Galra. In fact, right about now the Garrison were preparing to dredge that thing out of the sea.

Lance kind of just hoped they’d leave it with the fishes but Allura insisted that it needed to be studied. Lance could tell she was itching to get her hands on it, to figure out where it came from and how it ran. 

And she wasn’t wrong. The threat of a future attack was always looming so the paladins and the rest of the Garrison were determined to be prepared.

Thus, the training room.

“Come on, Keith,” Lance whines, feeling like his arms were going to fall off, Bayard heavy in his hands. Today, it was just Team Voltron in the room, Keith announcing a surprise training session at the crack of dawn. “We’ve been training for like four hours…”

“Three hours, 42 minutes,” Pidge says, face down in the smooth Garrison floors. She threw in the towel at least an hour ago despite Keith's nagging. She refused to budge, fatigue and exhaustion rooting her to the floor.

Keith frowns, arms folded. “The training is important. We never know when the Galra or Haggar will come back and we need to be ready no matter what.” He snorts. “The Blade trains their _recruits_ far harder than this.”

“Yeah but we’re not Galra,” Hunk wheezes, leaning heavily on his blaster (was that safe?). His hair stuck to his temples and his trademark headband had slipped down his forehead over one eye. “We’re just soft squishy humans, man.”

“Speak for yourself, Hunk,” Lance says with a sniff. “There is nothing _squishy_ about me.”

“Ha!” Pidge laughs into the ground. Lance sticks a tongue out at her even if she can't see it. Rude.

“I handled it just fine,” Keith says, stone-faced and stern in a way that reminded Lance of Kolivan. Like he was trying to mimic his mentor.

“Yes,” Allura says, putting away her Bayard and looking far better than the rest of them, her skin dewy and not single white hair out of place. That stupidly strong Altean strength and endurance. “But you’re half Galra. Perhaps that grants you more stamina than your fellow humans?”

Keith blinks owlishly, brows furrowing as if he hadn’t thought of that.

Lance blinks at that too because that hadn’t even crossed his mind either. He just figured Keith was fueled by angst, justice and man pain. Mostly angst. 

“No part of him even _looks_ Galra,” Pidge says, picking her face up off the floor, chin resting on the cold metal. Her glasses look a little bent, smushed against her face as brown eyes glare up at Keith in defiance.

Allura purses her lips, eyes sparkling in thought. “Well, yes that is a little odd. But we don't know very much about-“

“Quit talking about me like I’m a science experiment,” Keith snaps, hitting the blade of his sword (the Bayard one) against the floor with a clang. “We only get time to train once a week. We have to take advantage of that!”

“Shiro never pushed us this hard…” Pidge mutters and Lance sucks a breath in through his teeth. Oh shit.

Keith goes rigid, expression going blank. There’s a moment of silence where Hunk just freezes like a rabbit in danger and Allura has a hand to her mouth. Pidge only manages to glare for a few seconds more before it seems to dawn on her too and she slides her glare away guiltily.

“Fine. That’ll be all for today,” Keith says, voice even but Lance can see the clench of his fingers and the way his shoulders slump. The stern command and confidence he channeled as leader crumbling all at once.

“Are you sure?” Hunk asks warily, glancing between Keith and the door.

“Yeah.” Keith turns away and walks over to the training floor console. “Dismissed.”

They all hesitate for a moment, Pidge in particular, before packing up their things and slowly heading for the door. More often than not they gave Keith room when he got in a funk like this, dragged down by the weight of mantle of leader passed on to him. They tried to avoid those kind of comments… but sometimes they would slip out. The comparisons to Shiro. He’d certainly grown a lot during his time with the Marmora, living on a time whale and junk, but Lance could still see a little bit of that angry teenager, furious and indignant over the decision of the Black Lion.

They were big shoes to fill.

And it wasn’t like Keith was wrong... The Galra _were_ coming. They _did_ need more training. When Lance lunged at Zethrid back when she was threatening to torture Pidge he was smacked away like a limp ragdoll in just seconds. Kind of embarrassing really.

At one point when Lance doubted himself and his position in the team, Keith was there for him in his own awkward way… and Keith was now in a similar position, faced with the daunting task of fulfilling the role as their leader. And he's really trying his best.

So, Lance lingers.

“What?” Keith growls, not looking away from the console.

“Um well… I was thinking…” Lance shuffles, rubbing at his sweaty neck. God his arms hurt. “Maybe I could use some more training… with the sword. And you know… uh since you’re kinda the pro at the sword thing I was just thinking…”

“You don’t have to stick around, Lance,” Keith says flatly.

“No really!” Lance exclaims. “It could really help me out!”

There is a moment where Lance is just staring worriedly at the back of Keith's bare neck, his mullet pulled back (which is a good look actually, 9/10 from Lance). He expects Keith to shut him out and storm off...

Keith turns, his eyes guarded but with a glimmer of soft hope that makes a funny bubbly feeling bloom in Lance's chest, like the gentle fizz of soda. Lance beams, suddenly extremely glad he stuck around. Keith's lips twitch upward into something a little less grim and the feeling makes Lance feel lighter than air. He did that. He made Keith smile, even just a little.

“Really?” Keith asks.

“Yeah! I haven’t had as much practice with it.” He waves his sword around haphazardly, suddenly full of renewed energy. “So… maybe some sparring? The Gladiator just isn’t the same.”

“Sure.” And now Keith is grinning and Lance gives a mental fist pump at successfully cheering up Keith... Although the other paladin's grin is more of a sharkish smirk… “Just don’t expect me to go easy on you.”

Lance’s arms are already screaming in protest but he just laughs and readies his Bayard. “I can take it,” he scoffs. “Bring it on mullet man!”

…

Another hour later Lance wonders if he could just… throw his arms away. They will never be the same with the shuddering aches and pains radiating from shoulder to fingertip. Honestly, they feel like they’ll just pop off.

Lance groans and winces as their blades clash again. He’s going to feel this training for a week.

Still, he hangs on, parrying away Keith’s blows, swords crashing and glancing off each other. Keith is relentless, pressing forward, purple eyes laser-focused on Lance. He’s managed to fend him off but too late Lance realizes he’s been backed into a wall, shoulder blades bumping into the cold metal behind.

“Now what?” Keith says, seriously, sword leveled at Lance. “You’ve let me back you into a corner. Your options are limited because you let _me_ control the flow of the fight.”

Lance chuckles breathlessly, face hot. “Well not like I’ve ever been the dominant one.”

Keith blinks, thick dark brows going up in surprise.

“In a fight!” Lance adds, realizing that might have come out somewhat suggestive. “I-I’m more of a chill, go with the flow go kind of guy ya know?”

“R-right,” Keith says, clearing his throat, clearly embarrassed, and Lance blinks as an idea comes over him. A devious idea and he just can’t help himself.

He leans in, one finger gently tapping the tip of the blade at his chest and grins Cheshire wide. He flutters his lashes. “But if it was _you_ I’d let you dominate me anytime~”

Keith makes a funny choking sound, ears going pink and his grip goes lax...

“Ha!” Lance cheers triumphantly, knocking the blade from Keith’s hand. He points his sword at Keith, arms trembling and heart pounding. “How do you like that? Maybe I could just flirt my way ou-”

His moment of triumph and gloating is cut short in a flash when a hand grabs him by the collar, knocks his Bayard away and then Lance is splayed on the floor, head spinning and wondering what the hell just happened.

Keith just threw him on the floor like he weighed nothing.

Lance is about to protest, ask what the hell is wrong with Keith and why can't take a joke when all verbal functions die somewhere in his throat.

The red paladin hovers over him, one hand by his head and the other still fisted in his shirt. His thick bangs shade his forehead, the glow of his eyes-

Hang on. Lance blinks because he’s pretty sure that Keith’s eyes are actually glowing, like a literal glow stick, the whites of his eyes bleeding yellow and the look is decidedly… primal. It is a familiar pair of eyes but not on Keith.

“Don’t,” Keith begins seriously, glaring down at Lance. “Don’t _ever_ do that in a fight. You’ll get yourself killed.”

Lance opens his mouth, but he doesn’t know what to say. Does Keith know his eyes can do that? Did everyone know that and Lance just missed that little tidbit of info? He licks his lips and his heart thuds when he sees Keith’s sharp eyes track the sweep of his tongue, like a predator tracking the scurrying of its prey.

“I-It was just a joke,” he laughs weakly, finally finding his voice. It's hard to think when Keith has a knee between his legs, the top of his thigh brushing his crotch, and Lance is fascinated by the heated gold eyes, fine lashes and muscled shoulders over him an-

“I think that’s enough for today,” Keith says suddenly, dropping Lance’s collar and pulls away, leaving Lance feeling kind of exposed and bare on the floor. “Good job.”

“Th-thanks,” Lance says absently, sitting up, heart pounding and stomach fluttering like a net of butterflies.

“You okay?”

He rubs at the back of his head and looks up at Keith. His eyes are as they usually are, irises dark against the bright whites of his eyes. Human. He isn't looking at Lance though, focusing on the toe of his boot, expression unreadable.

“Yeah…” He starts and then glares at Keith. “Must have just hit my head, you jerk! I can’t believe you just…”

From there it ends up in one of their usualarguments, the two of them bickering and quipping at each other as they collect their things to head out, squabbling all the way down the hall. 

By dinner time, happily enjoying Hunk’s cooking, Lance has totally dismissed what he saw as some weird trick of the light or the rattling his brain took. Or maybe the exhaustion of training. 

Because… well, there was no way he actually saw Galra eyes on Keith, right?

… _Right?_


	2. Chapter 2

The second time around things are a little harder to dismiss.

Lance knew Keith was strong. Always had a little more muscle on him even when he was a lean mean angry teen. Emphasis on angry. 

And Lance wasn’t kidding when he called Keith taller and grizzled. His shoulders had gotten broader, arms bulkier and just overall looked like he was built a little sturdier. Strong. He wasn’t Shiro levels of beefcake or anything. But it was still noticeable. At least to Lance… not that he spent any significant amount of time watching Keith. Totally didn’t note the way his old shirts fit a little snugger across the chest or pulled a little tighter around the sleeves. 

It showed especially during training. Or rather was felt. Lance’s arms were still aching from the strength of Keith’s blows during that sparring session from hell. 

None of those changes were odd though. Keith had aged two years (was it two years? Thinking about it made Lance’s head hurt) and roughed it out in the wilderness. Anyone would be taller and a little more grizzled after that. 

But Lance didn’t realize exactly how strong until a week after their training session. 

“Ok…” he mutters, sweeping the scope across the field as he tries to find his vanishing target. “Where did you go lizard man?“ 

“Visuals, Lance!” James barks from below through his communicator. “Where is he?” 

Lance grits his teeth. “Hang on!” A catches a flash of green in his crosshairs and spots the spotted lizard alien climbing the outside of the hideout. “James! On your six! Climbing the wall! Nadia you’ve got another on your ri- uh… left!” 

His hearts pounds heavily in his chest from his perch. It had been some time since one of these missions and still his nerves get to him. He never lets it show, never lets it affect his ability to pull the trigger on his rifle but if someone were to put their ear to the ground next to him right now they could probably hear his heart thudding against it. 

The Garrison had gotten an anonymous tip that some shifty-looking figures had made camp in an abandoned Galra base just outside the city. No one could say who or what they were but there had been some mention of smuggled weapons. The base appeared to just be a shell, no power or anything, but Shiro asked a few of them to go and check it out. Just to be safe. 

So that was how Lance ended up on the roof of a hollowed out building, propped up on his elbows, watching James, Nadia and Keith’s backs through his scope as they fought off a band of smugglers, wielding some truly insane weapons. 

“On your six, Samurai,” Lance says, pulling the trigger and hitting an alien behind Keith in the thigh. The alien dropped his blaster and went down. Lance had his Bayard on nonlethal but that leg would be smarting for a while. 

“Thanks... Sharpshooter,” Keith grunts, parrying away another attacker and disarming him. Watching Keith fight was nothing short of hypnotic, his already smooth fighting style having transformed into something powerful and sinuous after his time with the Marmora. It was like watching a panther take down its prey, dual swords as his claws. Good thing he was only using the backs of his blades or these guys would be ribbons.

“You guys are adorable,” Nadia laughs, voice crackling. “You got any other cute nicknames for each other?” 

“Oh, yeah. I’ve got loads-” Lance spots someone skittering away, hits him in the butt, and swings back to Keith. “Mullet, Texas, Grumpy Pants McGee…” 

“Lance,” Keith says sharply and Lance has to stifle a giggle. He feels his heart calm a bit, the banter here familiar even with Nadia and James. 

“Well, they’re all accurate,” James says. Lance looks to see him tying down a group of smugglers. They’d be taken to the Garrison for questioning and all their weapons confiscated. Pidge was already up to her ears in work but she’d probably be giddier than hell to get her hands on these babies. 

"Can I call you Grumpy Pants from now on?" Nadia teases, dodging the furious swipes of what looks like a weasel with four arms. 

“No, you can't,” Keith grumps. 

"Oh, so Lance is special huh?" 

"You bet your ass I am," Lance says smugly. Keith doesn't give that a response, busy cuffing another smuggler. 

It isn’t their usual team, the rest of the paladins far too busy with their own things, but they work surprisingly well together and make quick work of it, rounding up all the smugglers and securing them. Lance sighs in relief, happy that things had gone so easily. 

But of course, just as he thinks that, the universe has to be a bitch about it. He spots something charging from the gutted hideout. Something big and… oh shit. And headed right for James. Lance is quick but even with two quick shots into the bulk of the alien, it doesn't even flinch. 

“Ja-” 

Before he can even get the warning out Keith is suddenly there, sliding between the thing and James, stance wide and arms out. Lance’s heart stops. 

“Keith!” 

It hits the other paladin with the force of a charging rhino and Lance feels his stomach flip and his body runs cold at the sight. 

But then he realizes that this big alien, big enough to rival Zethrid or Kolivan, hasn’t steamrolled the smaller paladin. Instead, Keith is hand to hand with the thing, meeting a beast three times his size head-on. And actually holding him back. Lance can see the effort it takes to hold the bigger alien, Keith’s arms trembling as if they’ll give out any moment. He can hear his ragged breathing and grunting through his communicator. 

“Nadia!” Lance shouts into his helmet. 

“Hang on!” Nadia replies. He’s pretty certain she’s already running to Keith’s position but Lance refuses to take his eyes off Keith to check- 

Lance blinks. The other paladin is in his Marmora outfit, the hood fallen back and face mask gone to reveal the mess of black hair and his face. He has a good view from up here and… He blinks his eyes a few more times in disbelief, certain his lens must be malfunctioning somehow. Or he’s imagining things. Or both. 

Because there is no way this is happening again. 

Keith’s eyes are yellow. That bright golden glow obvious even in the harsh desert sun. They glitter fiercely and Lance can _see_ them change through his lens, gold flooding the whites like ink bleeding across paper. Keith’s dark brows are furrowed, his teeth clenched, and suddenly it's like a switch is flipped in him. 

_Impossibly_ , Keith starts pushing back. Lance’s mouth falls open. The hulking alien seems startled by that too, its feet slipping against the ground for purchase as Keith step by step shoves him back from James, who appears to have lost movement in his legs. 

“Incoming!” Nadia appears from above, leaping off a rock and landing on the alien's shoulders. Armed with a pair of high voltage stunners on her knuckles (bless Pidge that little evil genius) she rams both fists into either side of its bulbous head. Lance closes his mouth and cranks up the rifle power, firing at its left leg. It rears back, pitching Nadia off, but it's enough. A weird sound rumbles through the communicator and Lance watches as Keith snaps a fist into the alien’s chest. 

Lance swears he hears something like a crack, even from here. 

Everything is utterly still for a moment, silent save for Keith’s ragged breathing and the rampant pounding of Lance’s heart in his ears. Then the alien shudders, eyes rolling back, and crumples. 

He sees Nadia stand, picking up her glasses and wiping dirt off on her suit. “Wow,” she says finally, pushing her glasses back up her nose. 

“Thanks, Nadia,” Keith wheezes, slumping against a rock. Lance jumps slightly as Keith glances up to where he is as if he can stare right at Lance through the scope. “You too..." He gives a crooked grin. "Sharpshooter.” 

Not a sliver of yellow is to be seen. His eyes are normal. Just like before, it comes and goes so quickly that Lance can’t help but doubt his own eyes… but for some reason, this time, Lance can’t bring himself to wave it off. 

“Quiznak, Keith, you scared the shit out of me,” he groans into his helmet. "What were you thinking?" 

“I handled it. You don’t need to worry about me, Lance,” Keith says, voice deep and hoarse in Lance’s ears. “Can you call it in so we can get these guys picked up?” 

“Yeah, yeah. I’m on it," Lance mutters. He can and will worry! He had done his fair share of reckless things but Keith was king at jumping headlong into trouble without sparing it a second thought. What if he couldn't have held that thing back? He might have died!

Lance sets his Bayard to the side, the scene below now faraway, as the gears in his head spin endlessly.

It wasn’t his imagination this time… Right? And if it wasn’t this time… doesn’t that mean it wasn’t last time either?  There on the training room floor, pinned by those wild yellow eyes… that actually happened. 

And that show of strength… it occurs to Lance that Keith was maybe using a fraction of his strength in the training room against him. With that kind of strength, he could probably easily lift Lance over his head. With one hand. Or maybe one finger. 

He presses his lips together, cheeks warm at the thought. Then that means… 

Lance shakes his head as he calls it in.

No. It couldn’t be. Half alien or not he is jumping to waaay too many conclusions here. His mom did say he always had an overactive imagination. As a kid, he was 100% certain his 4th-grade math teacher was a vampire... the evidence at the time was compelling, ok?

So, Keith was a little stronger than most humans. Big deal. He knew that. Massive as that alien was maybe it was really light... or really weak. Maybe all that bulk was flab.

As for Keith’s eyes… well, clearly his Bayard was acting up. It was a centuries-old piece of magical alien tech after all. Probably had some bugs or whatever. Maybe there was something wrong with the lens. Maybe he could ask Hunk or Pidge to take a look at it... or maybe this would be an Allura problem? 

Lance frowns as he waits for Veronica to answer. All of those excuses are lame and half-assed. And he knows it. 

He just can't shake it. He can still see the way those familiar purple eyes changed into something foreign and well… 

... Alien. 

**Notes for the Chapter:**

> After season 8 I wasn't sure if I should continue working on this but in the end I'm still Klance and Galra Keith garbage, neither of which season 8 had enough of so I'm back on my bullshit.

**Author's Note:**

> Have I ever mentioned I'm trash for Galra Keith? I'm trash for Galra Keith.
> 
> Takes place post season 7.


End file.
